diff --git a/modules/anagrafiche/ajax/select.php b/modules/anagrafiche/ajax/select.php
index ae612368d..6e6a1a38f 100755
--- a/modules/anagrafiche/ajax/select.php
+++ b/modules/anagrafiche/ajax/select.php
@@ -430,10 +430,13 @@
         $user = auth_osm()->getUser();
         $id_azienda = setting('Azienda predefinita');
 
-        $query = "SELECT * FROM (SELECT '0' AS id, 'Sede legale' AS `nome_sede`, CONCAT_WS(' - ', \"".tr('Sede legale')."\" , (SELECT CONCAT (`citta`, IF(`indirizzo`!='',CONCAT(' (', `indirizzo`, ')'), ''),' (', `ragione_sociale`,')') FROM `an_anagrafiche` |where|)) AS descrizione UNION SELECT `id`, `nome_sede`, CONCAT_WS(' - ', `nome_sede`, CONCAT(`citta`, IF(`indirizzo`!='',CONCAT(' (', `indirizzo`, ')'), '')) ) FROM `an_sedi` |where| ORDER BY `nome_sede`) AS tab |filter| ORDER BY descrizione";
+        $query = "SELECT * FROM (SELECT '0' AS id, 'Sede legale' AS `nome_sede`, CONCAT_WS(' - ', \"".tr('Sede legale')."\" , (SELECT CONCAT (`citta`, IF(`indirizzo`!='',CONCAT(' (', `indirizzo`, ')'), ''),' (', `ragione_sociale`,')') FROM `an_anagrafiche` |where|)) AS descrizione UNION SELECT `id`, `nome_sede`, CONCAT_WS(' - ', `nome_sede`, CONCAT(`citta`, IF(`indirizzo`!='',CONCAT(' (', `indirizzo`, ')'), '')) ) FROM `an_sedi` |where_sedi| ORDER BY `nome_sede`) AS tab |filter| ORDER BY descrizione";
 
         $where[] = '`id`='.prepare($id_azienda);
         $where[] = 'deleted_at IS NULL';
+        $where_sedi[] = '`id_anagrafica`='.prepare($id_azienda);
+        $where_sedi[] = 'deleted_at IS NULL';
+        $query = str_replace('|where_sedi|', 'WHERE '.implode(' AND ', $where_sedi), $query);
 
         // filtro in base alle sedi abilitate dell'utente
         if ($user->gruppo != 'Amministratori') {
diff --git a/tests/AnagraficheCompanyLocationsSelectorTest.php b/tests/AnagraficheCompanyLocationsSelectorTest.php
new file mode 100644
index 000000000..c7ccf0c7b
--- /dev/null
+++ b/tests/AnagraficheCompanyLocationsSelectorTest.php
@@ -0,0 +1,19 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+
+class AnagraficheCompanyLocationsSelectorTest extends TestCase
+{
+    public function testCompanyLocationsUseTheCompanyForeignKey(): void
+    {
+        $source = file_get_contents(__DIR__.'/../modules/anagrafiche/ajax/select.php');
+        preg_match("/case 'sedi_azienda':(?<selector>.*?)case 'referenti':/s", $source, $matches);
+
+        $selector = $matches['selector'] ?? '';
+
+        $this->assertStringContainsString('FROM `an_sedi` |where_sedi|', $selector);
+        $this->assertStringContainsString("\$where_sedi[] = '`id_anagrafica`='.prepare(\$id_azienda);", $selector);
+        $this->assertStringContainsString("\$where_sedi[] = 'deleted_at IS NULL';", $selector);
+        $this->assertStringContainsString("str_replace('|where_sedi|', 'WHERE '.implode(' AND ', \$where_sedi), \$query)", $selector);
+    }
+}